大数相乘--极简单的思路

大数相乘，面试常见的题型，如何计算两个打算相乘？

<pre style="font-family: 'Lucida Sans Typewriter'; font-size: 12pt; background-color: rgb(255,255);"><pre name="code" class="java">public class Test1 {
    public void multi(char[] a,char[]b){

        int alen = a.length;
        int blen = b.length;

        //用于存放最后计算出来的结果
        int[]s = new int[alen+blen];

        for (int i = 0; i < s.length; i++) {
            s[i] = 0;
        }
        //计算，（此时s中的某一个元素的值可能大于9）
        for (int i = 0; i < alen; i++) {
            for (int j = 0; j < blen; j++) {
                s[i+j+1] += (a[i]-'0')*(b[j]-'0');
            }
        }
        //进位处理
        for (int i = alen+blen-1; i >= 0; i--){
            if(s[i] >= 10){
                s[i-1] += s[i]/10;
                s[i] %= 10;
            }
        }

        print(s);
    }

    public void print(int [] s){
        int i = 0;
        while(s[i] == 0){
            i++;
        }
        for (; i < s.length; i++){
            System.out.print(s[i]);
        }
    }

    public static void main(String[] args) {
        String a = "36";
        String b = "36";
        char[] aa = a.toCharArray();
        char[] bb = b.toCharArray();

        Test1 test1 = new Test1();
        test1.multi(aa,bb);
    }
}